1. Field of the Invention
The present invention relates to a position detecting apparatus, a position detecting method and an electronic component carrying apparatus. More particularly, the present invention relates to a position detecting apparatus, a position detecting method and an electronic component carrying apparatus, which acquire the image of a terminal of an electronic component and detect the position of the electronic component by image processing.
2. Description of the Related Art
FIG. 1 shows the configuration of a conventional testing system 100. The testing system 100 includes a testing apparatus 102 for judging the quality of an electronic component 101 by applying test signals to the electronic component 101, a socket 103 for fixing the electronic component 101, a test head 104 for connecting the electronic component 101 fixed to the socket 103 and the testing apparatus 102 electrically and an electronic component carrying apparatus 106 for carrying the electronic component 101. The electronic component carrying apparatus 106 includes a tray 108 for holding the electronic component 101 to be tested and a carrying unit 110 for carrying the electronic component 101 between the tray 108 and the socket 103. The electronic component carrying apparatus 106 takes out the electronic component 101 from the tray 108, at which the electronic component 101 is arranged, carries it to the socket 103 and mounts it on to the socket 103. In addition, the electronic component carrying apparatus 106 removes the electronic component 101 tested from the socket 103 and carries it to the tray 108 classified corresponding to the test results.
FIGS. 2A and 2B show a state in which a terminal 112 of the electronic component 101 and a pin 114 of the socket 103 are in contact with each other. In order to test the electronic component having a plurality of terminals accurately, it is necessary to mount the electronic component 101 onto the socket 103 exactly. That is, as shown in FIG. 2A, it is preferable that the pin 114 of the socket 103 is in contact with a center of the terminal 112 of the electronic component 101 vertically. As shown in FIG. 2B, if the pin 114 of the socket 103 is in contact with the terminal 112 of the electronic component 101 deviating from the center of the terminal 112 or in contact with the terminal 112 of the electronic component 101 on a slant, the electrical resistance increases at the contact point, problems such as deterioration of waveforms of test signals, increase of the timing error and the like occur. In addition, if the electronic component 101 is fixed to the socket 103 in the state in which the pin 114 of the socket 103 deviates from the terminal 112 of the electronic component 101, the electronic component 101 might be broken as well.
FIG. 3 shows the configuration of the carrier 116. In the electronic component carrying apparatus 106, the electronic component 101 is positioned to the socket 103 by using the carrier 116. The carrier 116, which is a case for containing the electronic component 101, is formed by molding of, e.g., plastic. In the carrier 116, a concave part 118 of a rectangle shape is formed, so that the electronic component 101 is contained and fixed into the concave part 118. In addition, a hole 120 is provided on a lower surface of the carrier 116, and thus the terminal 112 of the electronic component 101 is coupled to the pin 114 the socket 103 electrically via the hole 120. The concave part 118 has the same shape as the electronic component 101, so that the electronic component 101 can be contained in the concave part 118 without a gap. Accordingly, when the electronic component 101 is positioned by using the carrier 116, a carrier 118 that fits with every shape of the electronic component 101 is needed.
However, these days, the kind of the electronic component 101 varies and the shape and size of it become various. Therefore, according to the shapes of the electronic component, it is inevitable to produce and purchase various kinds of the carrier 116, and thus the cost of production is increased. In addition, the design and production of the carrier 118 that fits with the shape of the electronic component 101 takes time, so that the launch of the production has to be postponed.
In addition, recently, the electronic components used for mobile communication devices such as a mobile phone becomes small in size and thin in thickness, and the number of the terminals are extremely increasing as the electronic component becomes highly integrated and multi-functional. Accordingly, the terminal of the electronic component becomes miniaturized and the pitch becomes shortened in regard to the arrangement interval. For example, if the terminal of the electronic component is a solder ball, the diameter of the solder ball becomes small up to 0.3 mm and the arrangement interval becomes up to 0.4 mm. In this way, if the terminal of the electronic component becomes miniaturized and the pitch becomes shortened in regard to the arrangement interval, there is a problem that it is impossible to position the terminal 112 of the electronic component 101 and the pin 114 of the socket 103 with high accuracy in a method of positioning the electronic component 101 by using the carrier 116 as shown in FIG. 3.
In order to solve the problem, an electronic component carrying apparatus (cf. Japanese Patent Application Publication No. 1993-275518) for positioning the electronic component 101 to the socket 103 is suggested, wherein it picks up the image of the terminal 112 of the electronic component 101 by a CCD camera and measures the position of the terminal 112 of the electronic component 101 by using an image processing method.
However, if light is applied to the electronic component 101 in a vertical direction, a substrate, on which the terminal 112 is formed, is liable to reflect the light, so that there is a problem that the difference of brightness between the terminal part and the substrate part becomes small and an clear image of the terminal 112 cannot obtained, and accordingly it is impossible to detect the position of the terminal 112 accurately.